Okay guys. What could it be?

[coupe]

New distributor. Accel Billetech.
Troubleshooting the EGR:
I unplugged EVS (EGR vacuum solenoid) and car wouldn't start. Reconnected it, started car, and hooked direct vacuum up to EGR & idle drops, then bumps back up normal & runs fine...exhaust smell is a bit less "rich" too doing this.(computer is doing what it needs to). Pulled codes again & of course, got the EVS (since I had unplugged it). I happen to have a new one so I replaced it anyway (this valve controls the EGR function).

No change.

Tommy, I will be trying that ProM...might have to come across some "freebie" 30#ers too. Just happen to know where some are.

[LeeH]

Originally Posted by coupe

New distributor. Accel Billetech.
Troubleshooting the EGR:
I unplugged EVS (EGR vacuum solenoid) and car wouldn't start. Reconnected it, started car, and hooked direct vacuum up to EGR & idle drops, then bumps back up normal & runs fine...exhaust smell is a bit less "rich" too doing this.(computer is doing what it needs to). Pulled codes again & of course, got the EVS (since I had unplugged it). I happen to have a new one so I replaced it anyway (this valve controls the EGR function).

No change.

Tommy, I will be trying that ProM...might have to come across some "freebie" 30#ers too. Just happen to know where some are.

Well Dale and I were talking on the phone and he suggested using a breakout box to watch sensor voltages. There are a few things though that dont sound right, The car should still run without the EGR sensor plugged in and the rough idle should continue with vacuum applied to the EGR valve(EGR open). This of course introduces spent exhaust gas into the intake which is for all purposes mostly inert gas which causes the rough idle. Unmetered air is another possibility, EFI is nice but it has a way of masking certain problems.

[Dale McPeters]

Originally Posted by LeeH

Well Dale and I were talking on the phone and he suggested using a breakout box to watch sensor voltages. There are a few things though that dont sound right, The car should still run without the EGR sensor plugged in and the rough idle should continue with vacuum applied to the EGR valve(EGR open). This of course introduces spent exhaust gas into the intake which is for all purposes mostly inert gas which causes the rough idle. Unmetered air is another possibility, EFI is nice but it has a way of masking certain problems.

Yep it should still start with the EVP/EGR unplugged.
Just stepped out to the shop and tried it out on the
blue car, it started fine. Of course the engine light
came on and set codes.

By the way coupe I think it is broke....

[LeeH]

Originally Posted by Dale McPeters

Yep it should still start with the EVP/EGR unplugged.
Just stepped out to the shop and tried it out on the
blue car, it started fine. Of course the engine light
came on and set codes.

By the way coupe I think it is broke....

There ya go trying to break the blue car again

[coupe]

True. But it was the EGR vacuum solenoid unplugged that made starting difficult. Unplugging EGR sensor doesn't do anything but throw check engine light and sure-enough, doing that showed up in the continuous memory as a code 33. And opening EGR causes idle to drop, but then stabilize...my understanding is when it opens, it senses that & leans out?? but maybe thats when cruising ?

Another interesting code today from "continuous memory" is 96. Fuel Pump Secondary circuit failure. EEC not sensing voltage on Fuel pump monitor circuit. Could this have "deteriorated" suddenly? Could this cause the problem? NOt even sure what this is doing.

I went ahead & erased the CM memory. Maybe it will try to adapt to something tomorrow.

I'm about ready to see what a carburetor costs these days.

[coupe]

I had another thought. When setting my TPS, I shoot for .99v on idle, but if I reference the "ground" to the frame, I get lower reading than if I reference ground to say throttle-body or something closer to TPS. What is causing this? The values are the same if key is "on" but car is not running... Why is reference to ground different when running? If I referenced the wrong one, the setting would be around 1.15 instead of .99 I'll see if it works. That sounds like a possibility.

[86GT]

Code 96 is sensing the return voltage from the fuel pump relay. I had this when I did the SD to MAF conversion. I had to run a wire from the fuel pump relay back to the EEC. I can not remember what pin it was but if you would like I can look it up.

If the car runs then the obviously the pump and relay are working and it would be the feedback.

There should be no difference on the reference. Check pin 60 on the EEC and the ground strap on the back of the motor. There should be a big ground strap going from the drivers side head to the firewall. There should also be another ground wire on the same lug for the O2 sensors.

[QWKSNKE]

could the fuel pump be going out?

[coupe]

I will check ground. I thought pump was the problem earlier. It's got a new pump & filter. No change.

The TPS voltage thing didn't do shit. It's not a TPS adjustment. Seems like it's not timing or fuel delivery; I've checked about everything. I'm really leaning toward EGR. I'm gonna block it off. Or get an LS1.

[93Cobra#2771]

Just hitting on the obvious that hasn't been mentioned:

• Are you SURE you don't have any vacuum leaks? Have you checked recently, including your inlet ducting?
• Any exhaust leaks PRIOR to the O2's?
• What is the mechanical condition of the motor - does it burn a little oil, or have a lot of miles on it? (possible carbon deposits/hot spots/preignition?)